Relation Between the Chemical Structure and the Biological Activity of Hydroxystilbenes Against Botrytis cinerea

Abstract A Spanish strain of pepper mild mottle virus (PMMV-S) (A lonso et al. 1989) can be differentiated from the Italian PMMV (W etter et al. 1984) by the responses of Capsicum spp. with resistance genes to tobamoviruses, by radioimmunoassay and by the electrophoretic mobility of their viral particles. Moreover, the analysis of the electrophoretic mobility of the viral particles in agarose gels and that of the viral coat proteins in polyacrylamide-urea gels are reliable and rapid techniques for distinguishing PMMV isolates from other members of the tobamovirus group and thus can be used for diagnostic purposes. These results support the proposal of grouping these pepper viruses, including the "pepper strains" of TMV, as a new tobamovirus subgroup (PARES 1985, BETTI et al. 1987, WETTER et al. 1987, ALONSO et al. 1989).     

Role of afferent input in muscle atrophy.

It is well known that soleus muscle of rat atrophies following spaceflight or hindlimb suspension (Ohira et al., 1992). It is, further, reported that the electromyogram (EMG) of soleus muscle disappears immediately in response to unloading by exposure to actual micro-g environment (Kawano et al., 2002; Leterme and Falempin, 1998) and by hindlimb suspension of rats (Alford et al., 1987; Ohira et al., 2000). However, the EMG level is increased gradually to the control level following 7-10 days of continuous hindlimb suspension (Alford et al., 1987; Ohira, 2000), while muscle atrophy is progressing (Winiarski et al., 1987). We previously reported that reduction of the EMG level of rat soleus in response to actual micro-g environment, created by a parabolic flight of a jet airplane, was closely associated with a decrease of the afferent input recorded at the L5 segmental level of spinal cord (Kawano et al., 2002). However, it is still unclear how the EMG level of soleus muscle adapts to unloading condition. The current study was performed to investigate the responses of soleus EMG and both afferent and efferent neurogram at the L5 segmental level of spinal cord to acute (20 seconds) and chronic (14 days) unloading.     

广东省南雄盆地白垩系—第三系交界恐龙绝灭问题

广东省南雄盆地中的红层可划分为三个群五个组,大致代表了晚白垩世—始新世的沉积.根据绝对年龄、古地磁测定结果和脊椎动物化石组合性质的综合分析,位于地磁极性带 29R 上部的坪岭组和上湖组之间的分界线被确定为 K/T 界线.对晚白垩世恐龙蛋的研究表明,不同"种"的恐龙蛋是在地磁极性带 29R 的中、下部,也就是说在白垩系—第三系交界之前20～30万年期间绝迹的.而且在这一时期内,所有已发现的蛋壳中,绝大多数蛋壳的厚度和显微结构都显示出明显的病理特征,例如根据随机取样统计,Macroolithus yaotunensis 蛋壳异常结构的出现率,最高可达75%.产生病态恐龙蛋壳的生理机制可以根据发生在现生鸟类的相同病理特征来解释.进一步分析恐龙蛋壳的微量元素和稳定同位素组成,结果显示, Pb, Cu, Mn 等9种元素丰度变化在这一时期达到最大峰值, δ~(18)O 也出现正异常.在这一基础上提出,微量元素的污染和气候突然的变化妨碍了正常蛋壳结构的形成,导致了恐龙的绝灭.这一绝灭过程大约经历了20～30万年.     

Rats’ (Rattus norvegicus) temporal discrimination of brief auditory stimuli: How does it compare with that of humans (Homo sapiens) and zebra finches (Taeniopygia guttata)?

The present study with rats replicated an experiment on the ability of zebra finches and humans to discriminate among brief auditory stimuli (see Weisman et al., 1999, Experiment 2). We trained rats with 27 3-kHz tones that varied in duration from 10 ms to 1420 ms. Reinforcement was contingent on responding (approaching the food well) to the nine medium-durations range tones (56-255 ms) but not to the nine short-durations range (10-46 ms) or long-durations range tones (309-1420 ms). Rats also received post-discrimination transfer tests with 2 kHz and 4 kHz tones that varied over the same durations as the 3 kHz tones. Rats acquired the temporal discrimination to a slightly lower level of accuracy than seen in finches or humans by Weisman et al. (1999). We tested for transfer of the temporal discrimination to find that rats, similar to humans (data from Weisman et al., 1999), transferred to untrained 2-kHz and 4-kHz tones at levels approaching accuracy to that achieved to the trained 3-kHz tone. By contrast, zebra finches (data from Weisman et al., 1999) failed to transfer their discrimination to the trained tone. We conclude that (a) rats discriminate among tone durations at least as well as they do among auditory frequencies and (b) rats like humans, but unlike finches, are insensitive to absolute pitch in their temporal discrimination.     

Isolation of a growth and mitosis inhibitory peptide from mouse liver

The isolation of a liver peptide that inhibits the growth, mitosis rate and thymidine incorporation in regenerating liver is described. The peptide has the structure Pyroglu-gln-gly-ser-asn, and the deamidated forms are also active. The peptide probably belongs to a class of growth inhibitors with a high degree of tissue specificity. Two such peptides have previously been isolated from the epidermis (Reichelt et al. 1987) and from colonic tissue (Skraastad et al. 1987).     

Isolation of a growth and mitosis inhibitory peptide from mouse liver

The isolation of a liver peptide that inhibits the growth, mitosis rate and thymidine incorporation in regenerating liver is described. The peptide has the structure Pyroglu-gln-gly-ser-asn, and the deamidated forms are also active. The peptide probably belongs to a class of growth inhibitors with a high degree of tissue specificity. Two such peptides have previously been isolated from the epidermis (Reichelt et al. 1987) and from colonic tissue (Skraastad et al. 1987).     

Small Intestinal Bacterial Overgrowth in Seven Dogs with Gastrointestinal Signs

In small intestinal bacterial overgrowth (SIBO) syndrome the small intestine is colonized by bacteria in excess of 105 colony-forming units (CFU)/ml or g (Batt et al 1983, Williams et al 1987, Strombeck & Guilford 1990). In dogs, SIBO has only recently been recognized as a cause of gastrointestinal signs like diarrhea (Strombeck et al 1981, Batt et al 1983, Batt & McLean 1987, Batt et al 1988). No demonstrable underlying anatomic or functional predisposition is identified in most cases of canine SIBO. However, most of the reported cases have been on German shepherds and dogs suffering from pancreatic insufficiency (Williams etal 1987; Simpson etal 1990).     

A new HaeIII polymorphism at the D21S13 locus

Summary DNA markers in the pericentromeric region of human chromosome 21 have shown linkage to a gene for Familial Alzheimer disease (FAD; St. George Hyslop et al. 1987). The limited informativeness of probes for the loci D21S13 and D21S16 have hindered precise mapping of the FAD locus and analysis of non-allelic heterogeneity in FAD (Schellenberg et al. 1988; St. George-Hyslop et al. 1987). We recently described a new EcoRII polymorphism at the D21S13 locus that was very informative in a large FAD pedigree (Pulst et al. 1990a, b). We now report another polymorphism for the D21S13 locus that further increases the informativeness of this locus.     

A new EcoRI polymorphism at the D21S13 locus

Summary The D21S13 locus has shown linkage to a gene for familial Alzheimer disease (FAD) on chromosome 21 (St. George-Hyslop et al. 1987). The limited informativeness of probes for this locus have hindered precise mapping of the FAD locus and analysis of nonallelic heterogeneity in FAD (Schellenberg et al. 1988; St. George-Hyslop et al. 1987). We describe a new EcoRI polymorphism at the D21S13 locus that may be useful for the further study of FAD families.     

Nonlegume hemoglobin genes retain organ-specific expression in heterologous transgenic plants.

Hemoglobin genes from the nitrogen-fixing nonlegume Parasponia andersonii and the related non-nitrogen-fixing nonlegume Trema tomentosa have been isolated [Landsmann et al. (1986). Nature 324, 166-168; Bogusz et al. (1988). Nature 331, 178-180]. The promoters of these genes have been linked to a beta-glucuronidase reporter gene and introduced into both the nonlegume Nicotiana tabacum and the legume Lotus corniculatus. Both promoters directed root-specific expression in transgenic tobacco. When transgenic Lotus plants were nodulated by Rhizobium loti, both promoter constructs showed a high level of nodule-specific expression confined to the central bacteroid-containing portion of the nodule corresponding to the expression seen for the endogenous Lotus leghemoglobin gene. The T. tomentosa promoter was also expressed at a low level in the vascular tissue of the Lotus roots. The hemoglobin promoters from both nonlegumes, including the non-nodulating species, must contain conserved cis-acting DNA signals that are responsible for nodule-specific expression in legumes. We have identified sequence motifs postulated previously as the nodule-specific regulatory elements of the soybean leghemoglobin genes [Stougaard et al. (1987). EMBO J. 6, 3565-3569].     

Response to Frederic Bretzner et al. "Target populations for first-in-human embryonic stem cell research in spinal cord injury"

We address concerns raised in this issue by Bretzner et al. (2011) by explaining the rationale for including subjects with subacute, neurologically complete spinal cord injuries in the Phase 1 trial of GRNOPC1. We also present elements of the informed consent process that minimize the likelihood of therapeutic misconception.     

On the neuronal basis of figure-ground discrimination by relative motion in the visual system of the fly

A fly can discriminate an object (figure) from its background on the basis of motion information alone. This information processing task has been analysed, so far, mainly in behavioural studies but also in electrophysiological experiments (Reichardt et al., 1983). The present study represents a further attempt to bridge the gap between the behavioural and the neuronal level. It is based on behavioural and electrophysiological experiments as well as on computer simulations. The characteristic properties of figureground discrimination behaviour impose specific constraints on the spatial integration properties of the output cells of the underlying neuronal network, the heterolateral interactions in their input circuitry, as well as on the range of variability of their response. These constraints are derived partly from previous behavioural studies (Reichardt et al., 1983), partly, however, from behavioural response characteristics which have not been addressed explicitly so far. They are interpreted in terms of one of the alternative model circuits shown by Reichardt et al. (1983) to be sufficient to account for figure-ground discrimination. It will be demonstrated, however, that this can be done equally well by means of a further alternative model circuit. These constraints are used in the electrophysiological analysis for establishing visual interneurones as output elements of the neuronal network underlying figure-ground discrimination.In the behavioural experiments on figure-ground discrimination as well as on the optomotor course control the yaw torque generated by the tethered flying fly under visual stimulation was used as a measure for the strength and time course of the reaction. Therefore, it has initially been proposed that the three Horizontal Cells, which are regarded as the output elements of the neuronal network underlying the optomotor reaction (e.g. Hausen, 1981), might also control yaw torque generation in figure-ground discrimination (Reichardt et al., 1983). New behavioural data show, however, that the Horizontal Cells do not meet all the constraints imposed on the presumed output cells of the figure-ground discrimination network: (1) The Horizontal Cells are not sensitive enough to motion of small objects. (2) The heterolateral interactions within their input circuitry are not in accordance with the behavioural data (see also Reichardt et al., 1983). (3) The variability found in the time course of certain components of the yaw torque response to relative motion of figure and ground cannot be explained by their response characteristics. Hence, the Horizontal Cells cannot account for figure-ground discrimination on their own and additional output cells of the optic lobes with different functional properties are required to accomplish this task.     

1H NMR assignment and secondary structural elements of human transforming growth factor alpha

The 1H NMR spectrum of human transforming growth factor alpha (hTGF-alpha) has been completely assigned, and secondary structural elements have been identified as a preliminary step in determining the structure of this protein by distance geometry methods. Many of these structural elements closely correspond to those previously found in a truncated human EGF [Cooke et al. (1987) Nature (London) 327, 339-341] and murine EGF [Montelione et al. (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 5226-5230]. These include the presence of an antiparallel beta-sheet between residues G19 and C34 with a type I beta-turn at V25-D28, a type II beta-turn at H35-Y38, and another short beta-sheet between residues Y38-V39 and H45-A46.     

Testing for density-dependent effects in sequential censuses

Summary In response to Gaston and Lawton (1987), we evaluated the ability of four statistical procedures to detect density dependence. We used data from the same 16 populations as Gaston and Lawton (1987). In each population, density dependence had been previously established with techniques that use more extensive data. The major axis test (Slade 1977) was rarely (3 populations of 16) capable of detecting density dependence. The autocorrelation test (Bulmer 1975) detected density dependence in 5 of 16 species (14 of 59 tests overall). The randomization procedure (Pollard et al. 1987) detected density dependence in 7 of the 16 data sets (10 of 59 tests overall). The simulation procedure (Vickery and Nudds 1984) detected density dependence in 5 of the 16 data sets (11 of 59 tests overall). We suggest that not all annual census data taken from populations subject to density-dependent effects will actually show evidence of such effects. We conclude that Pollard et al. 's (1987) randomization procedure is the best test for detecting density dependence in sequential census data but it is not as powerful as more elaborate techniques (k-factor analysis, experimentation, etc.), nor is it meant to replace more extensive analyses.     

Cytochemical studies of the vascular endothelium

Cytochemical methods have been used to examine the vascular endothelium. With hemeproteins and immunocytochemistry, investigators have demonstrated the pathways that blood-borne molecules can take to gain access to the extravascular space (Ghitescu et al. 1986; Milici et al. 1987; Schneeberger and Karnovsky 1971; Simionescu et al. 1975). These same cytochemical methods have also provided evidence that morphologically similar endothelia may have different permeability properties (Hart and Pino 1985b, 1986; Pino 1985; Pino and Essner 1980, 1981). Differences in the location and chemical composition of cell surface moieties have been ascertained with enzyme digestion methods, lectins, and cationic ferritin (De Bruyn and Michelson 1978; Pino 1984c, 1986a, b; Simionescu et al. 1981a). The author hopes that he has provided the reader with representative examples of how investigators have used these cytochemical methods for their studies. As new methods are developed and applications are found for existing techniques such as ultracryomicrotomy (Milici et al. 1987) and colloidal gold markers (Pino 1987b), cytochemistry will remain a fundamental tool for the study of the structure and function of the vascular endothelium.     

A model of the single atrial cell: relation between calcium current and calcium release

The hypothesis that calcium release from the sarcoplasmic reticulum in cardiac muscle is induced by rises in free cytosolic calcium (Fabiato 1983, Am. J. Physiol 245) allows the possibility that the release could be at least partly regenerative. There would then be a non-linear relation between calcium current and calcium release. We have investigated this possibility in a single-cell version of the rabbit-atrial model developed by Hilgemann & Noble (1987, Proc. R. Soc. Lond. B 230). The model predicts different voltage ranges of activation for calcium-dependent processes (like the sodium-calcium exchange current, contraction or Fura-2 signals) and the calcium current, in agreement with the experimental results obtained by Earm et al. (1990, Proc. R. Soc. Lond. B 240) on exchange current tails, Cannell et al. (1987, Science, Wash. 238) by using Fura-2 signals, and Fedida et al. (1987, J. Physiol., Lond. 385) and Talo et al. (1988, Biology of isolated adult cardiac myocytes) by using contraction. However, when the Fura-2 concentration is sufficiently high (greater than 200 microM) the activation ranges become very similar as the buffering properties of Fura-2 are sufficient to remove the regenerative effect. It is therefore important to allow for the buffering properties of calcium indicators when investigating the correlation between calcium current and calcium release.     

Pseudempleurosoma gibsoni n. sp., a new ancyrocephalid monogenean from Paralonchurus brasiliensis (Sciaenidae) from off the southeastern coast of Brazil

Pseudempleurosoma gibsoni n. sp. (Monogenea: Ancyrocephalidae) is described from the oesophagus of Paralonchurus brasiliensis (Steindachner) from off the coast of Brazil. The type-species of Pseudempleurosoma Yamaguti, 1965, P. carangis Yamaguti, 1965, is redescribed and the diagnosis of the genus is amended. Metadiplectanotrema Gerasev et al. 1987 is considered synonym of Pseudempleurosoma. This genus now contains four species, including P. carangis, P. caranxi Gerasev et al., 1987 n. comb., P. myripristi Gerasev et al., 1987 n. comb. and the one new species.     

Cytokine immunoreactivity in plasma does not change after moderate endurance exercise.

We investigated whether increased concentrations of circulating cytokines may be responsible for exercise-induced priming of blood neutrophils (J. A. Smith et al. Int. J. Sports Med. 11: 179-187, 1990). The plasma concentrations of tumor necrosis factor-alpha, interleukin- (IL) 1 beta, IL-6, granulocyte-macrophage colony-stimulating factor, and neopterin in trained and untrained human subjects were measured by immunoassay before and after 1 h of cycling at 60% of maximal oxygen uptake. C-reactive protein and creatine kinase (CK) were also measured before and 24 h after exercise as markers of the "acute-phase response" and muscle damage (C. Taylor et al. J. Appl. Physiol. 62: 464-469, 1987), respectively. The small changes in the plasma concentrations of cytokines or neopterin observed after exercise in both trained and untrained subjects were not significantly different to those found in a control group of nonexercised subjects. However, untrained subjects did exhibit an acute-phase response (P = 0.04) 24 h after exercise without additional release of CK into plasma. Baseline training differences were confined to a twofold elevation in CK activity (P = 0.04). The results show that circulating cytokines are unlikely to be responsible for the priming of neutrophil microbicidal activity observed after moderate endurance exercise (J. A. Smith et al. Int. J. Sports Med. 11: 179-187, 1990).